Ticket #38852: 38852.1.diff

src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php

@@ -991 +991 @@
                 }
 
                 // Parent.
-                if ( ! empty( $schema['properties']['parent'] ) && ! empty( $request['parent'] ) ) {
-                        $parent = get_post( (int) $request['parent'] );
-
-                        if ( empty( $parent ) ) {
-                                return new WP_Error( 'rest_post_invalid_id', __( 'Invalid post parent ID.' ), array( 'status' => 400 ) );
+                if ( ! empty( $schema['properties']['parent'] ) && isset( $request['parent'] ) ) {
+                        if ( 0 === (int) $request['parent'] ) {
+                                $prepared_post->post_parent = 0;
+                        } else {
+                                $parent = get_post( (int) $request['parent'] );
+                                if ( empty( $parent ) ) {
+                                        return new WP_Error( 'rest_post_invalid_id', __( 'Invalid post parent ID.' ), array( 'status' => 400 ) );
+                                }
+                                $prepared_post->post_parent = (int) $parent->ID;
                         }
-
-                        $prepared_post->post_parent = (int) $parent->ID;
                 }
 
                 // Menu order.

tests/phpunit/tests/rest-api/rest-pages-controller.php

@@ -371 +371 @@
                 $this->assertEquals( 0, $new_data['menu_order'] );
         }
 
+        public function test_update_page_parent_non_zero() {
+                $page_id1 = $this->factory->post->create( array(
+                        'post_type' => 'page',
+                ) );
+                $page_id2 = $this->factory->post->create( array(
+                        'post_type' => 'page',
+                ) );
+                wp_set_current_user( self::$editor_id );
+                $request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/pages/%d', $page_id2 ) );
+                $request->set_body_params( array(
+                        'parent' => $page_id1,
+                ) );
+                $response = $this->server->dispatch( $request );
+                $new_data = $response->get_data();
+                $this->assertEquals( $page_id1, $new_data['parent'] );
+        }
+
+        public function test_update_page_parent_zero() {
+                $page_id1 = $this->factory->post->create( array(
+                        'post_type' => 'page',
+                ) );
+                $page_id2 = $this->factory->post->create( array(
+                        'post_type'    => 'page',
+                        'post_parent'  => $page_id1,
+                ) );
+                wp_set_current_user( self::$editor_id );
+                $request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/pages/%d', $page_id2 ) );
+                $request->set_body_params( array(
+                        'parent' => 0,
+                ) );
+                $response = $this->server->dispatch( $request );
+                $new_data = $response->get_data();
+                $this->assertEquals( 0, $new_data['parent'] );
+        }
+
         public function test_get_page_with_password() {
                 $page_id = $this->factory->post->create( array(
                         'post_type'     => 'page',